1. Field of the Invention
Embodiments of the invention generally relate to fabrication processes, and more specifically, for treatment processes and deposition processes while forming a material on a substrate.
2. Description of the Related Art
In the field of semiconductor processing, flat-panel display processing or other electronic device processing, vapor deposition processes have played an important role in depositing materials on substrates. As the geometries of electronic devices continue to shrink and the density of devices continues to increase, the size and aspect ratio of the features are becoming more aggressive. Feature sizes of about 45 nm or smaller and aspect ratios of 10, 20, 30 or greater are more frequently desired during fabrication processes. While conventional chemical vapor deposition (CVD) processes have proved successful, aggressive device geometries require an alternative deposition technique, such as atomic layer deposition (ALD). During an ALD process, chemical precursors or reactant gases are sequentially introduced into a process chamber containing a substrate. Generally, a first precursor gas is administered into the process chamber and is adsorbed onto the substrate surface. A second precursor gas is administered into the process chamber and reacts with the first precursor to form a deposited material. A purge step is typically carried out between the delivery of each precursor gas and may be a continuous purge with a carrier gas or a pulse purge between the delivery of the precursor gases.
Atomic layer deposition processes have been successfully implemented for depositing dielectric layers, barrier layers and conductive layers. Dielectric materials deposited by ALD processes for gate and capacitor applications include hafnium oxide, hafnium silicate, zirconium oxide and tantalum oxide. Generally, an ALD process provides a deposited material with lower impurities and better conformality and control of film thickness when compared to a CVD process. However, an ALD process usually has a slower deposition rate than a comparable CVD process for depositing a material of similar composition. Therefore, an ALD process that reduces the overall fabrication throughput may be less attractive than the comparable CVD process. By utilizing a batch tool, productivity may be improved without sacrificing the benefits provided by ALD processes.
A batch deposition process may be used to maintain or increase throughput during a fabrication process by simultaneously processing multiple substrates within a single chamber. However, batch processes using CVD techniques remain limited due to the smaller geometries of modern devices. Current batch deposition processes utilizing ALD techniques may have an incubation delay prior to the onset of a constant deposition rate. The incubation delay may be attributed to a homogenous terminated surface of functional groups, such as hydrides, hydroxides, silicides and the like. Also, current ALD batch deposition processes may form high levels of particulates and other contaminants that end-up on the substrate surface. Contaminated surfaces may further increase incubation delay, as well as cause defects within the deposited material that lead to poor device performance.
Therefore, there is a need for a deposition process to decrease the incubation delay and reduce contaminants on a substrate surface prior to depositing a material, preferably, a hafnium oxide material during an ALD batch process.